Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753996AbdDOMTJ (ORCPT ); Sat, 15 Apr 2017 08:19:09 -0400 Received: from mail-wr0-f195.google.com ([209.85.128.195]:36853 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751955AbdDOMTG (ORCPT ); Sat, 15 Apr 2017 08:19:06 -0400 From: Michal Hocko To: linux-mm@kvack.org Cc: Andrew Morton , Mel Gorman , Vlastimil Babka , Andrea Arcangeli , Jerome Glisse , Reza Arbab , Yasuaki Ishimatsu , qiuxishi@huawei.com, Kani Toshimitsu , slaoub@gmail.com, Joonsoo Kim , Andi Kleen , David Rientjes , Daniel Kiper , Igor Mammedov , Vitaly Kuznetsov , LKML Subject: Date: Sat, 15 Apr 2017 14:17:31 +0200 Message-Id: <20170415121734.6692-1-mhocko@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170410110351.12215-1-mhocko@kernel.org> References: <20170410110351.12215-1-mhocko@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 716 Lines: 12 Hi, here I 3 more preparatory patches which I meant to send on Thursday but forgot... After more thinking about pfn walkers I have realized that the current code doesn't check offline holes in zones. From a quick review that doesn't seem to be a problem currently. Pfn walkers can race with memory offlining and with the original hotplug impementation those offline pages can change the zone but I wasn't able to find any serious problem other than small confusion. The new hotplug code, will not have any valid zone, though so those code paths should check PageReserved to rule offline holes. I hope I have addressed all of them in these 3 patches. I would appreciate if Vlastimil and Jonsoo double check after me.